Click on the checkboxes shown on the right to see how the various frequencies contribute to the graph.
Look for large magnitude coefficients (sine or cosine), as these are associated with frequencies which
contribute most to the associated stock plot. If you find a large magnitude coefficient which dramatically
changes the graph, look at the associated "Period" in weeks, as you may have found a significant recurring
cycle for the stock of interest.

Right click on the graph above to see the menu of operations (download, full screen, etc.)

Fourier Analysis

Using data from 1/3/2000 to 10/9/2017 for SPIR (SPIRE COR), this program was able to calculate the following Fourier Series: